California law limits how far invention assignment reaches

The record

California Labor Code Section 2870 states that a provision requiring an employee to assign inventions to an employer “shall not apply” to an invention “developed entirely on his or her own time without using the employer's equipment, supplies, facilities, or trade secret information,” unless the invention either relates, at conception, to the employer's business or anticipated research, or results from work performed for the employer. The statute, added in 1979 and amended in 1991, further states in subsection (b) that any assignment provision purporting to reach an invention meeting that carve-out “is against the public policy of this state and is unenforceable.” A companion statute, Section 2872, requires an employer whose agreement contains an assignment clause to give the employee written notice, at the time the agreement is signed, that it does not apply to inventions Section 2870 excludes, and places the burden of proving the exclusion applies on the employee.

What the documents establish

The statutory text sets three conditions that must all be met for the carve-out to apply: the invention must be developed entirely on the employee's own time, without the employer's equipment, supplies, facilities or trade secret information, and must not relate to the employer's business or anticipated research or result from work performed for the employer. Section 2872's notice requirement does not void an assignment agreement that omits it; the statute addresses only where the burden of proof falls in a later dispute. Washington State's RCW 49.44.140, cited only to show California is not an outlier, imposes a materially similar three-part test and notice requirement, confirming a recognized state-law pattern rather than one state's unusual rule.

The operating read

A founder or engineer signing, or drafting, an invention-assignment agreement should read Section 2870 as a floor the parties cannot contract around in California: subsection (b) makes broader assignment language unenforceable to the extent it reaches an excluded invention, regardless of what the contract says. The more practical risk sits with the notice requirement: a company that skips the Section 2872 notice has not lost the underlying protection, but has given up a documentary record that could help settle a later dispute over whether an invention falls inside or outside the carve-out. This is an editorial reading; it should not be extended to another state's statute without checking that state's own text.

What to check before you decide

Before assuming Section 2870 protects an invention, or drafting a clause around it, check the following.

• Did the invention rely on any employer equipment, supplies, facilities, or trade secret information, even partially, during its development?
• Does the invention relate to the employer's actual or demonstrably anticipated research or business at the time of conception, regardless of when it was reduced to practice?
• Was the Section 2872 notice given in writing at the time the agreement was signed, and is that documentation still available?

Because the statute's protection depends on facts about when and how an invention was made, the closest primary record for any dispute is the invention disclosure and the underlying agreement, not commentary about Section 2870.